A touch position sensor can detect the presence and location of a touch by a finger or by another object, such as a stylus. A touch position sensor, for example, can detect the presence and location of a touch within an area of an external interface of the touch position sensor. In a touch sensitive display application, the touch position sensor enables direct interaction with what is displayed on the screen, rather than indirectly with a mouse or touchpad.
Touch position sensors can be attached to or provided as part of devices with a display, such as computers, personal digital assistants, satellite navigation devices, mobile telephones, portable media players, portable game consoles, public information kiosks and point of sale systems. Touch position sensors have also been used as control panels on appliances.
There are a number of different types of touch position sensors, such as resistive touch screens, surface acoustic wave touch screens, capacitive touch screens, etc. A capacitive touch screen, for example, may include an insulator coated with a transparent conductor in a particular pattern. When a finger or other object touches the surface of the screen, there is a change in capacitance. This change in capacitance may be sent to a controller for processing to determine the position of the touch.
There also are a number of different types of fingerprint sensors. Examples include optical fingerprint sensors, thermal fingerprint sensors and capacitive fingerprint sensors.